In0.49Ga0.51P/In0.20Ga0.80As PHEMTs on a GaAs substrate were fabricated using a selective wet etch process for the gate recess. The recess width was varied by changing the recess etch time. Atomic Force Microscopy was used to measure the width of the recess. We studied the effect of the gate recess width on the DC and microwave properties of 0.9 Ám gate length transistors. The best performance was obtained for a recess etch time of 1 minute, resulting in a recess width of 0.22±0.05 µm. For this recess etch width, we measured a maximum drain current of 530 mA/mm, a transconductance of 320 mS/mm, fT of 31 GHz, and fmax of 106 GHz.